The term "phospholipid" is generic to several different types of compounds originating in the mammalian cell and containing long chain fatty acid esters of glycerol attached to various polar groupings. Lecithin, a phosphatidic acid ester of choline, is one of a group of such phospholipids, having structure I below ##STR1## wherein Z and Z.sup.1 are long straight chain alkyl or alkenyl radicals and Q is ##STR2## a phosphocholyl radical. A related substance is plateletactivating factor (PAF)--see Demopoulos et al, J. Biol. Chem., 254, 9355 (1979)--having structure Ia below ##STR3## in which there is an ether linkage on C-1, a short chain fatty acid ester (acetate) at C-2, Z is C.sub.16 -C.sub.18 alkyl and Q has its previous meaning. A number of analogues of PAF have been synthesized. Among these are compounds of structure Ib below described in FEBS Letters, 14 29 (1982)--see also Modell et al, Can. Res., 39, 4681 (1979) which describes the activity of such compounds in selectively destroying Meth A sarcoma cells-- ##STR4## where Z.sup.2 is alkyl or H; and Z and Q have their previous meanings.
A recent EPO patent 103,877 (3-28-84), Derwent No. 83598, discloses 5-phosphocholyl derivatives of methyl D-xylofuranoside in which there is a long chain alkyl (octadecyl) ether on the C-2 or C-3 hydroxy. The compounds have antitumor activity. Derivatives of deoxy pentoses are not contemplated therein.